New construction of home da nang help

Hello my wife have some land in da nang and we are looking to build a home there but terrified of the difference in construction and legalities there?  We have contacted a architect and construction company  but wanted some outside help and advice in what we need to know to protect ourselves. 
Some key points:
We know that vietnam have different quality standards with construction.  We know we have to watch out for concrete mix being mix incorrectly and to double check plumbing and electrical work.  Such as sewer pipes with no back flow and p trap in all sinks,  breaker on each floor.
Our other concern is warranty on the construction and other contractual agreements clauses we need to be aware of and what we need to have in the contract? 
We got an estimate based on square footage, but we have had heard where suddenly the estimated price goes up as the construction is being done?  I understand material may go up depending on market supply and demand but what can we do to protect ourselves if the contractor starts charging more for stuff? 

Thanks ahead of time we are newbies at this

If you contract a decent builder this shouldn't happen. Get your wife to check the contract,ask the architect if they have any knowledge of the builder. I wouldn't be using hand mixed concrete, I would be asking for ready mixed concrete. If you have understanding of good building practised you will spot it when they try to cheat. I would buy the fittings for the house, lights,toilets,cabinets, you will save money as the builder will add money on top for purchasing it them. My background is construction and I must say the average finish of homes in Viet Nam is very,very poor.

Thanks for the quick reply!  When you say poor?  Do you have any examples? Im so glad we found this forum.  The amount of knowledge and expertise here are amazing

Poor finishing things such as paint on surfaces, poor grouting, poor quality doors and windows. Ask the builder for some addresses of properties that he has completed.

Does anyone have any recommendations of a good architect in da nang?

I doubt batched concrete in this country of cheaters is any assurance it is as specified. In commercial construction here they do perform slums tests on each batch delivered as well as pressure testing. If I were building here I would endure the minor additional expense and at the very least have it pressure tested by a reputable lab. As I have already told the OP the PSI for foundation concrete should be 3000-3500 PSI. I you know someone up there that knows construction all you need to do is drive around and look at the building site. You can tell in seconds if they are good building contractors. But it needs to be someone that has experience in the field. I think one issue any multicultural family will have here is the very same thing that makes contractors seem indifferent to quality building standards. That is they seem to think if it is at all functional it is just fine. So it is very hard to get a bride onboard to beat the contractor over the head when they will not do as you want. They may run out of tan paint after 3 walls are painted and run get some more paint and paint the remaining wall pink. Hey it is painted, color match is just not that important.

Heck the company that was working on the new mass transit system was caught pumping mud into the columns where they were supposed to have pumped concrete. The pig farmers like to put a water hose down the throat of livestock before they goto market to get a false weight. Potatoes farmers buy potatoes fro China and put them in the ground in Dalat to get the look of the red clay dirt of Dalat then sell them as DL potatoes.
So I suspect the fella at a concrete batch plant 10 kilometers from your job site might put 40# of cement instead of the 50# required for 3000 PSI cement. Heaven knows what the little guy on site that mixes it by the yard might do.If he agrees 3000 PSI is warranted he MIGHT do it. But if he sees all concrete as functional he may not. Heck they still have not figured out how to put roof tile on correctly here.

I am building a 5 story house in Da Nang.  And it's very difficult to get proper budgeting information or to communicate your general needs.  We have bought materials seperate to labour and have a family member who watches over the use of the materials etc.  Our estimations show that the materials are getting used up at the right rate.   I believe we supervise the concrete getting mixed at the batch plant as well.    My final thought is that there are still many dodgee bits to the job so you just hope its' 200% over-engineered and they do 80% of a good job.

We also had to sack our first builder who was progressing at a snails pace.  We lost USD $2000 because of this.

Yeah they are probably selling your materials or using them in another job. They screw their socks on in the morning they are so crooked.  I would think it would be a nightmare to try and corral these folks enough to nuild a quality home. You have to be onsite and have eyes in the back of your head.

No I don't think we're getting ripped off like that.  My brother-in-law and mother-in-law are onsite 80% of the time.  They buy and count the materials etc.   Where columns have been hand mixed they could have used the vibrators a bit more to get the air out a bit better.   I'm a bit worried about the pre mixed concrete in the truck.  We've been using the concrete pump to get it onsite - a pretty fast way to build.  It's probably ok I will check with my Vietnamese engineer friend who's been watching the site to see how we know we're not being sold concrete with a low quantity of cement.

Get someone to ask the concrete company to do test pots on their concrete. You pick which truck to test and see the report.

The best and only way is to have each batch load that is delivered PSI tested. They will turn out some of the load then take a sample canister and send it off to a lab. There is will be tested under pressure. Here well worth the cost. I would not build here w/o having this test done. You can also have an onsite slump test. But Ibwould not worry about this to much as it is primarily a water content test which affects work ability. It issue if high rate if material usage really should be investigated. I have seen such things here cone from inside and outside the family. These people are very creative. Do you not get materials takeoff list when the plans were drawn up?

Not sure what the previous poster is referring to as " spit " Testing". But here if you settle for less than testing of each truck delivers then you are going to get screwed. All commercial construction here requires independent lab PSI testing.

ok but they could do the dodge based on who they think they're dealing with.  So you really need to test your own deliveries.

So how does it work.  If the concrete gets rejected but it's now made up the building - are they out with jackhammers?  Or is the threat of it being tested enough to stop the dodgee batches coming through.

I replied to your question of what happens if it is a bad batch etc. perhaps it did not get posted for some reason. So I will try again.
  For one your contract with the builder should have addressed the testing of each batch of concrete. And the testing lab works indepentaly for you or the architect. I have never seen anyone in the chain mix a bad batch, pour a bad batch when all players know when that truck arrives at the site it will be tested.
  The contract should have included this and that those involved will pick up the cost of jackhammer the bad pour and replacing it. NO ONE is going to let that happen when they know the work is being tested.

Quality in Asia is sub par. But there are good contractors.
They should be able to give you references. And u do have family on site to check things, very important.
Good luck to u and let us know how things turn out for you